A Study to Evaluate the Effect of a Single Dose of Digoxin on the Actions in the Bodies of Healthy Subjects After Having Taken Several Doses of YM178

Inclusion Criteria: * Female subject must be of non-child bearing potential, i.e. post menopausal, surgically sterilized (e.g. tubal ligation), hysterectomy in medical history, or must practice an adequate (double barrier) non-hormonal contraceptive method to prevent pregnancies * Body Mass Index ≥ 18.5 and \< 30 kg/m2 Exclusion Criteria: * History or presence of cardiac diseases, including arrhythmias (including 1st and 2nd degree atrioventricular heart blocks) * History of hypokalemia, hypercalcemia or hypomagnesemia * Any of the liver function tests (i.e. ALT, AST and Alkaline phosphatase) above the upper limit of normal at repeated measures * Any clinically significant history of asthma, eczema, any other clinically significant allergic condition or previous severe hypersensitivity to any drug (excluding non-active hay fever) * Any clinically significant history of gastrointestinal symptoms in the 4 weeks prior to admission to the clinical unit * A marked baseline prolongation of QT/QTc interval after repeated measurements of \> 450 ms, a history of unexplained syncope, cardiac arrest, unexplained cardiac arrhythmias or torsades de pointes, structural heart disease, or a family history of Long QT Syndrome (LQTS) * Regular use of any inducer of liver metabolism (e.g. barbiturates, rifampin) in the 3 months prior to admission to the clinical unit * Positive serology test for HBsAg, anti HAV (IgM), anti-HCV or anti-HIV 1+2